If I was near a mob it makes a game lag. For example, Pig, Cows, Sheep, Chicken, Zombie, Skeleton, Spider makes my camera hard to move. That happens to every gamemode. I was trying to fight out monsters, Zombie, skeleton, spider, creeper and enderman, Makes very laggy. My render was up to 5 out of 13 makes it still laggy to mobs. That's only I can stay away from mobs to stop the lag.
Check out my profile for bug reports I've reported to fix.